trans-Neptunian object

American  

[trans-nep-too-nee-uhn ob-jikt, ‐jekt, ‐-tyoo‐, tranz] / ˈtræns nɛpˈtu ni ən ˈɒb dʒɪkt, ‐dʒɛkt, ‐ˈtyu‐, ˈtrænz /

Or transneptunian object

noun

Astronomy.

1. any celestial object in our solar system whose orbit lies beyond Neptune, including Pluto: there may be some 70,000 trans-Neptunian objects orbiting 30–50 astronomical units from the sun, with diameters of at least 62 miles (100 km). TNO

---

trans-Neptunian object Scientific  

/ trăns′nĕp-to̅o̅n′ē-ən /

1. A celestial object that orbits the sun at a greater distance on average than Neptune.

---

Etymology

Origin of trans-Neptunian object

First recorded in 1920–25

Example Sentences

One object, 2013 FY27, is the ninth-brightest trans-Neptunian object known, and at roughly 760 kilometres across is among the largest objects in the outer Solar System.

From Nature